GLO Brilliant Personal Teeth Whitening Device, $199; sephora.com.The Claim: This system—which comes with a rechargeable base, a mouthpiece, 10 vials of hydrogen peroxide gel, and a lip-protecting balm—is meant to make your smile five shades brighter in five days. How it works: After sweeping the protective salve over your lips, apply the gel onto your teeth, activate the device, and insert the mouthpiece; wait eight minutes, then remove it, add more gel, and repeat the process three times. Make this your routine for five straight days to see full results. "There's an LED inside the mouthpiece," says creator Jonathan Levine, an N.Y.C. dentist. "When trapped with heat inside the mouth, it accelerates the whitening process" and doesn't cause sensitivity in users.
Expert Opinion: Sleek and user-friendly, it brightens after five days, "though results may vary from person to person," says N.Y.C. dentist Emanuel Layliev. But keep in mind, he says, "at-home systems are never as high in peroxide concentration as professional ones for safety reasons, so this is best used after an in-office whitening procedure to maintain the look."
Our Take: Once the piece was put in place, our tester got nervous. "I wasn't sure I'd make it through the first eight minutes, let alone 32, but it wasn't that uncomfortable, and once I got busy the time flew by," she says. "I washed dishes, watched TV, and filed my nails while the gel did its thing. Best of all, my teeth were three shades whiter in two days." Sensitivity issues? "I had some tingling afterward."Read MoreLess